Maintenance of an alert mental state of consciousness is important in many fields for many reasons. For example, the American Medical Association's Council on Scientific Affairs published a report indicating that driver drowsiness and fatigue are involved in at least about 1.5% of the nation's annual 6.3 million vehicle accidents. Of those accidents involving drowsiness, about 96% involved passenger vehicles; the remainder involved trucks. In addition to the transportation industry, many other fields incur substantial revenue and productivity losses due to individuals unintentionally transitioning from an alert state of consciousness to a non-alert state. Avoiding or delaying such transitions would have enormous economic and societal benefit.
Prior to this invention, no device existed which could prevent or delay the onset of an unintentional transition from an alert mental state to a non-alert state of consciousness through the monitoring of brain wave patterns. Instead, in order to prevent such transitions, various other approaches have been applied. For example, chemical stimulants have long been used in order to maintain an alert state of consciousness for a period longer than would be experienced absent the stimulant. Alternatively, in some fields time periods during which a particular function requiring that an alert state of consciousness be maintained have been established in order to ensure the desired level of consciousness is maintained throughout.
More recently, several devices have been developed which monitor and respond to physical manifestations of fatigue or drowsiness. For example, U.S. Pat. No. 5,402,109 describes an eyeglass-attachable alarm signal device designed to prevent automobile and truck drivers from falling asleep while driving. The device employs a small slide-adjustable light emitter which produces a beam of a narrow-band light to optically sense whether the driver's eyelids are opened or closed. The light beam is aimed across the surface of the driver's eye, just above the eyeball, between the eyelids, and it is sensed in the opposite corner of the eye by a light sensor. When the device detects that a driver's eyes have been closed for longer than a predetermined time, e.g., about one second, an electronic circuit activates an alarm.
Another device to monitor and restore alertness is described in U.S. Pat. No. 5,626,145. Specifically, that device automatically detects alertness in a subject by collecting brain wave data from a subject using an electroencephalogram or magnetoencephalogram. The brain wave data is then separated from other data, e.g., data resulting from eye blinks, chewing, and other movements not related to brain activity, using a zero phase quadratic filter. The non-brain wave data is then further analyzed to detect alertness. Thus, these devices do not monitor states of consciousness by analysis of brain waves or brain wave patterns, but instead rely on physical manifestations of states of consciousness.
In contrast, it is the object of this invention to provide devices which allow an alert state of consciousness to be maintained through the use of a device which monitors and interprets brain wave patterns of an individual wearing the device. When the device detects in the wearer a brain wave pattern associated with a non-alert state of consciousness, a transient physical stimulus is then provided to restore the desired mental state.